Ground connections around bridge rectifier in flyback converter

Question

I am designing a flyback converter and I am being told to make the ground net connections as shown in the image below.

I think this is colossally dumb because it eliminates PRI and SEC isolation. I have two questions about this that are safety and function related:

1. Will this create a short circuit that links NEUTRAL and LINE? It looks like it shorts one of the diodes in the diode bridge.
2. Even if we did not short the diode bridge and only shorted across PRI and SEC, will this cause the converter to become non-functional? I am unsure on this; yes I know that it removes the isolation, but I'm wondering whether even if we did this will it cause the converter to not work at all.
3. Is the best course of action to connect a capacitor across PRI and SEC?

Answer 1

Will this create a short circuit that links NEUTRAL and LINE? It looks like it shorts one of the diodes in the diode bridge.

Correct; it is really terrible advice.

Even if we did not short the diode bridge and only shorted across PRI and SEC, will this cause the converter to become non-functional? I am unsure on this; yes I know that it removes the isolation, but I'm wondering whether even if we did this will it cause the converter to not work at all.

It will still work but, as you state, isolation is lost.

Is the best course of action to connect a capacitor across PRI and SEC?

This is done a lot of the time to reduce conducted and radiated emissions from the isolated secondary winding circuits. It's usually in the region of 470 pF to 4.7 nF and, it has to be a properly rated capacitor for the job (with regards to safety).

I think this is colossally dumb

Sounds like that; now you can judge the skills of the person who told you this. This of course is a hidden benefit LOL.